The spleen sits just under your ribs in the upper, left portion of your abdomen and is responsible for filtering out old red blood cells, storing monocytes and collecting antibody covered bacteria and blood cells for removal from the body.

Red blood cells; the cells responsible for carrying oxygen to the body’s tissues, have a life span of about 4 months before the wear out. The monocytes in the spleen collect dying rbc’s and to recycle their constituents for use in the body. What can’t be recycled, is excreted by the kidneys and large intestine. Both urine and feces get their trademark colors, in part, from the waste products of red blood cells bilirubin and biliverdin. Monocytes are white blood cells that can either directly destroy dead red blood cells though a series of surface membrane chemical reactions or can differentiate into macrophages which resemble gobbling Pac-Men. Half of the body’s monocytes are stored in the spleen. Monocytes also travel through your body and migrate to damaged tissues when needed. Monocytes differentiate (mature) into macrophages to “eat up” dead cells, bacteria, or other waste products from damaged tissues.

Human Monocyte surrounded by red blood cells

The spleen’s monocytes are also responsible for eating up antibody coated bacteria and cells. Think of antibodies as little “please kill me” signs attached to the outside of cells. The body’s immune system has marked these antibody complexes for destruction. Monocytes will either ingest these complexes directly, or cause them to self destruct.

You can live without your spleen, but its absence will leave you more susceptible to infection. Splenectomy patients have a higher than average rate of death from pneumonia and a higher concentration of circulating monocytes – since their storage unit has been removed. Splenectomy patients also show a decreased response to some vaccinations. Without your spleen, you need to work harder to stay healthy to prevent disease.